Contactor device for a projectile with electric ignition



May 19, 195.9 FERRET 2,887,056

CONTACTOR DEVICE FOR PROJECTILE WITH ELECTRIC IGNITION Filed Jan. 10,1956 III lllllllillllllH ll lNl EN T e JE/w P2 212: T

United States atent O CONTACTOR DEVICE FOR A PROJECTILE WITH ELECTRICIGNITION Jean Ferret, Geneva, Switzerland, assignor to MothaTreumstitut, Vaduz, Liechtenstein, a corporation of LiechtensteinApplication January 10, 1956, Serial No. 558,300 Claims'priority,application Switzerland .lanuary ll, 1955 4 Claims.- (Cl; 102-70i2) Thisinvention relatestoelectrically operated contactor means for aprojectile, said means comprising a deformable nose cap adapted to comeinto electrical. contact with a similarly shaped electrically conductingshell positioned within the said nose cap.

In heretofore known contactor means, the electrically conducting shellwithin the nose cap is shaped similarly to that of the nose cap, and theouter surface of said shell is spaced, at all portions thereof, a fewmillimeters from the inner surface of the nose cap, and the nose cap isnsually fabricated from a light metal such as aluminum, therebyresulting in a relatively thin-walled, lightweight structure. Because ofthis nose-cap structure, projectiles having a firing means of this typeare diflicult to handle without producing a permanent deformation insome portion of the nose cap due to its thin wall, and in the handlingof such devices permanent deformations have frequently occurred in thenose cap, thereby leaving the so-deformed nose cap wall in short circuitwith the said inner shell. Since there are always provided safety meansfor preventing the firing of the projectile when there is electricalcontact between the nose cap and the inner shell, the projectile isrendered useless by any deformation in the nose cap of the firing means,for, if there were no safety means, H1116 projectile would explodeimmediately upon firing the s ot.

An object of this invention is to provide an electrically operatedcontactor means for a projectile, said means comprising a nose capfabricated of a material having an elastic memory, thereby enabling saidnose cap to resume its original shape after having been subjected to anyshock tending to deform it, the inner surface of said nose cap beingelectrically conducting for at least a portion thereof.

Other objects and features will become apparent from the followingdetailed description which is not intended to be limiting but is hereset forth to describe the preferred embodiments.

Figure l is a view in section of an embodiment of the contactor means ofmy invention.

Figures 2 and 3 are longitudinal sections of two additional embodimentsof my invention showing modifications of the head nose cap.

Fig. 4 is a cross-section on the line IVIV of Fig. 3.

The contactor device shown in Fig. 1, comprises a paraboloidal shapednose cap 1 of insulating synthetic resin, in the interior of said nosecap 1 is located a conducting part 2, also of insulating syntheticresin, and of which the relative position to the external nose cap isobtained by means of a ring 3 of insulating material.

The internal surface of the nose cap 1 is metal-coated, as is also theouter surface of the part 2. The material of which the nose cap 1 isconstructed has a sufficient elasticity or an elastic memory so as toreturn to its initial position after having been subjected to adeformation, resulting from a shock, causing it to come into contactwith the inner part 2. In this manner, if in the course ofmanipulations, or handling, the nose cap 1 receives a shock or iscrushed, it can resume its initial position by reason of its naturalelasticity or its elastic memory, so that, at the moment of firing theshot, there 15 not any contact between the parts 1 and 2, and thus theprojectile can function normally.

When the part 2 is also of deformable synthetic resin and the. head ofthe projectile is subjected to a shock or crushing, the nose cap 1 andthe part 2 can temporarily be deformed. and then resume their initialposition. However, thepart 2 may be of metal and sufficiently solid soas to resist shocks and crushing which may occur during manipulation, orhandling, of the projectile by troops.

The nose cap and the part 2 may also be of conducting synthetic resin sothat their internal and external surfaces, respectively, need not bemetallized.

Fig. 2 shows a second embodiment of the nose cap of the head of theprojectile. Said latter nose cap is formed by a casing 4 of materialhaving an elastic memory, comprising on its inner face a metalreinforcement, comprising a coiled spring 5 conforming with the innersurface or face of the nose cap.

In the embodiment of Figs. 3 and 4, the nose cap 1 is paraboloidalshaped and is provided with longitudinal internal ribs 6. As shown inFig. 4, each of the ribs 6 has a groove with which a steel Wire 7partially engages. Said steel wires form a metal reinforcement formingthe conducting parts of the internal surface of the nose cap and areadapted to close the electric contact with the inner part 2.

The upper and lower ends of the steel wires '7 are bent and embedded inthe material of the nose cap 1, as shown in Fig. 3. Near their lower endthe Wires 7 are in contact with a conducting ring 8, in the interior ofwhich is located an insulating ring 9, adapted to hold the internal part2 (not shown in Fig. 3) in position. The ring 8 is for the purpose ofplacing all the Wires 7 in electrical connection with a part of theignition circuit of the projectile.

The nose cap 1 and, if desired, the internal part 2 may, for example, beof polyethylene. Said parts may, meanwhile, be provided of other elasticmaterial, for example of rubber, or may even be constituted of a thinsheet of steel. However, in the latter case, the production of thearticle would be relatively complicated.

As clearly shown, the electrical firing circuit includes the connectingwires 100, the electric primer or detonator 102, and the electricbattery 104.

I claim:

1. An electrical contactor device for a projectile, comprising, incombination, a nose cap and an electrically conducting shell positionedwithin said nose cap and away from said nose cap, said nose cap beingformed of an insulating synthetic material having an elastic memory, ametal coating on the inner surface of said nose cap, the outer surfaceof said shell being spaced from said metal coating, and an electricalfiring circuit connected to said metal coating and to said shell,whereby said nose cap will resume its original shape after having beensubjected to a shock causing a deformation in being handled and wherebythe metal coating will electrically contact the outer surface of saidshell at the moment the projectile will hit the target to complete theelectrical firing circuit.

2. An electrical contactor device for a projectile, comprising, incombination, a nose cap and an electrically conducting'shell within andaway from said nose cap, said nose cap being formed of an insulatingsynthetic material having an elastic memory, a metal reinforce- "ment onthe inner surface of said nose'eap', said'metal reinforcement being acoiled spring contacting the inner surface of said nose cap, said metalreinforcement being spacedfrom the outer surface of said shell, and an Ielectrical firing circuit connected tosaid metal reinforcement' of saidnose cap and to said shell, whereby said nose cap will resume itsoriginal shape after having been subjected to a shockcausing. adeformation. in

being handled'and whereby said. metal reinforcementiwill' electricallycontact the outer surface of. said shell at I the moment the projectilewill hit the targetto complete the electrical'firing circuit.

3. An electrical contactor device for aprojectile, cornprising, incombination, :a paraboloidally shaped nose cap having a plurality ofcircumferentially spaced ribs I on its inner surface and an electricallyconducting shell.

= positioned within and awaytrorn said nose cap, said nose cap; beingformed, of a material having an elastic memory, the outer surface ofsaid shell being spaced from the inner surface ofsaid nose cap, saidnose cap I Being electrically conducting atsaidribs, and an electpositioned therein.

t References Cited in the file of this patent UNITED STATES PATENTS 7561,665 omatnrnain.. --;.;Ma ,20, 1944. 1,105,780 France July 6,1955,

